[net-next 02/13] igb: Update RXDCTL/TXDCTL configurations

Jeff Kirsher
2011-09-17T08:04:42Z

From: Alexander Duyck <alexander.h.duyck@intel.com>

This change cleans up the RXDCTL and TXDCTL configurations and optimizes RX
performance by allowing back write-backs on all hardware other than 82576.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
drivers/net/ethernet/intel/igb/igb.h | 5 +++--
drivers/net/ethernet/intel/igb/igb_main.c | 23 +++++++++--------------
2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 265e151..577fd3e 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -100,11 +100,12 @@ struct vf_data_storage {
*/
#define IGB_RX_PTHRESH 8
#define IGB_RX_HTHRESH 8
-#define IGB_RX_WTHRESH 1
#define IGB_TX_PTHRESH 8
#define IGB_TX_HTHRESH 1
+#define IGB_RX_WTHRESH ((hw->mac.type == e1000_82576 && \
+ adapter->msix_entries) ? 1 : 4)
#define IGB_TX_WTHRESH ((hw->mac.type == e1000_82576 && \
- adapter->msix_entries) ? 1 : 16)
+ adapter->msix_entries) ? 1 : 16)

/* this is the size past which hardware will drop packets when setting LPE=0 */
#define MAXIMUM_ETHERNET_VLAN_SIZE 1522
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 3cb1bc9..aa78c10 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2666,14 +2666,12 @@ void igb_configure_tx_ring(struct igb_adapter *adapter,
struct igb_ring *ring)
{
struct e1000_hw *hw = &adapter->hw;
- u32 txdctl;
+ u32 txdctl = 0;
u64 tdba = ring->dma;
int reg_idx = ring->reg_idx;

/* disable the queue */
- txdctl = rd32(E1000_TXDCTL(reg_idx));
- wr32(E1000_TXDCTL(reg_idx),
- txdctl & ~E1000_TXDCTL_QUEUE_ENABLE);
+ wr32(E1000_TXDCTL(reg_idx), 0);
wrfl();
mdelay(10);

@@ -2685,7 +2683,7 @@ void igb_configure_tx_ring(struct igb_adapter *adapter,

ring->head = hw->hw_addr + E1000_TDH(reg_idx);
ring->tail = hw->hw_addr + E1000_TDT(reg_idx);
- writel(0, ring->head);
+ wr32(E1000_TDH(reg_idx), 0);
writel(0, ring->tail);

txdctl |= IGB_TX_PTHRESH;
@@ -3028,12 +3026,10 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
struct e1000_hw *hw = &adapter->hw;
u64 rdba = ring->dma;
int reg_idx = ring->reg_idx;
- u32 srrctl, rxdctl;
+ u32 srrctl = 0, rxdctl = 0;

/* disable the queue */
- rxdctl = rd32(E1000_RXDCTL(reg_idx));
- wr32(E1000_RXDCTL(reg_idx),
- rxdctl & ~E1000_RXDCTL_QUEUE_ENABLE);
+ wr32(E1000_RXDCTL(reg_idx), 0);

/* Set DMA base address registers */
wr32(E1000_RDBAL(reg_idx),
@@ -3045,7 +3041,7 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
/* initialize head and tail */
ring->head = hw->hw_addr + E1000_RDH(reg_idx);
ring->tail = hw->hw_addr + E1000_RDT(reg_idx);
- writel(0, ring->head);
+ wr32(E1000_RDH(reg_idx), 0);
writel(0, ring->tail);

/* set descriptor configuration */
@@ -3076,13 +3072,12 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
/* set filtering for VMDQ pools */
igb_set_vmolr(adapter, reg_idx & 0x7, true);

- /* enable receive descriptor fetching */
- rxdctl = rd32(E1000_RXDCTL(reg_idx));
- rxdctl |= E1000_RXDCTL_QUEUE_ENABLE;
- rxdctl &= 0xFFF00000;
rxdctl |= IGB_RX_PTHRESH;
rxdctl |= IGB_RX_HTHRESH << 8;
rxdctl |= IGB_RX_WTHRESH << 16;
+
+ /* enable receive descriptor fetching */
+ rxdctl |= E1000_RXDCTL_QUEUE_ENABLE;
wr32(E1000_RXDCTL(reg_idx), rxdctl);
}

--
1.7.6